Fuel spray preparation is very important as it provides a means to have much finer droplets of fuel being ejected into the engine. U.S. Pat. No. 5,114,077 issued on May 19, 1992 to Mark Cerny and entitled "Fuel Injector End Cap" is assigned to a common assignee, is concerned about the prevention of fuel seepage from the end cap of a high pressure injector. However, it describes a spray generator in a high pressure fuel injector. A high pressure fuel injector has the fuel at pressures exceeding 4.0 Bar.
In '077 patent the spray generator is displaced adjacent and upstream from the valve seat member and has a plurality of passageways ending in an inclined passageway which directs the fuel tangential to the needle valve upstream of the sealing ring of the valve in the valve seat member.
Another U.S. Pat. No. 5,207,384 issued on May 4, 1993 to John J. Horsting and entitled "Swirl Generator For An Injector" is also assigned to a common assignee. In this patent the swirl generator is located adjacent to the outlet orifice of the injector. The swirl generator is a two piece device that is located in the conical valve seat and operates to direct the fuel tangentially to the valve seat. The function of the swirl generator is to impart a tangential flow to the fuel and to minimize the amount of residual fuel in the injector prior to opening.
A third patent, U.S. Pat. No. 5,271,563 issued on Dec. 21, 1993 to Cerny et al and entitled "Fuel Injector With A Narrow Annular Space Fuel Chamber" is assigned to Chrysler Corporation. This patent teaches a high pressure fuel injector wherein the fuel is directed tangentially to a volume surrounding the needle valve upstream of the valve seat. When the valve opens, this amount of fuel leaves the space and subsequent amounts of fuel are tangentially directed to the needle valve and have a swirling motion imparted to the fuel.